Conventionally, a sheet discharging device used in an image forming apparatus is generally provided with upper discharge roller pairs each having a driving discharge roller and a driven discharge roller brought into pressure contact therewith. Further, the following technique is known. That is, in order to provide a sheet being discharged with stiffness so as to prevent a leading end of the sheet being discharged from drooping down and from pushing out a sheet already discharged and placed on a discharge tray, the driving discharge rollers and the driven discharge rollers are arranged by being inclined by a predetermined angle θ. The driving discharge rollers and the driven discharge rollers are arranged symmetrically about a substantially central portion, in a widthwise direction perpendicular to a sheet transporting direction, of a sheet discharge path (e.g., JP-A-2004-35175). Specifically, two drive shafts of the driving discharge rollers are used, which are joined by a joint member in a state in which the drive shafts are inclined symmetrically about a widthwise substantially central portion of the sheet discharge path. According to such a construction, the driving discharge rollers and the driven discharge rollers are inclined, and the sheet is also curved in conformity with their inclination, so that the sheet is provided with stiffness and is discharged without drooping down.